Per The Unofficial Apple Weblog, just hours after releasing the first build of OS X 10.9 Mavericks without a “Developer Preview” label to AppleSeed members, Apple has issued the official “Golden Master” version of OS X 10.9 Mavericks to all developers.

A Golden Master build is the same, official version of software that will be released to customers. The fact that Apple has released the GM build to developers almost guarantees users will see the release of OS X 10.9 Mavericks sometime this month. OS X 10.9 Mavericks will introduce over 200 new features, notably iBooks for Mac, Maps for Mac, tabbed Finder, iCloud Keychain, Tags, and more.